Hitachi, Ltd.

Hitachi Information & Control Solutions, Ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi Engineering Co., Ltd.

Hidefumi Shirahama

Hideki Miyazaki

Yoshitaka Iwaji

Daisuke Maeda

Hiroyuki Hasegawa

Tsunehiro Endo

Norikazu Tokunaga

Ikuo Yamato

Kazuaki Tobari

Kenji Sakurai

Mitsuhiro Mishima

Yasuo Matsuda

Yoshimi Sakurai

Yutaka Suzuki

Kenichi Onda

Akira Kobayashi

Shigehisa Aoyagi

Kiyoshi Sakamoto

Yasuo Notohara

Keizo Shimada

Yoshiyuki Taguchi

Yuzo Morita

Tomofumi Okubo

Yoshiki Ito

Tsunehiro Endou

Yorito Jifuku

Yoshiaki Ajima

Tomoaki Mino

Takeshi Nagano

Mitsufumi Iwanaka

Youuji Ishida

Yoshiki Itou

Satoru Inukai

A synchronous motor including therein a three-phase inverter and position sensors, having a unit for calculating a digital input current value from the analog output of an input current detection circuit that detects the input current flowing into the DC input terminal of the three-phase inverter, and a digital feedback speed control unit for adjusting the amplitudes and frequency of the AC voltages outputted from the three-phase inverter in such a manner that the motor speed calculated by a motor speed calculation uniton the basis of the outputs of the position sensors approaches a speed command value received by a communication reception unit from outside the synchronous motor. The synchronous motor further includes therein a communication transmission unit for transmitting the input current value and the motor speed to outside the synchronous motor.

Synchronous motor and control method of synchronous motor

The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Apparatus and method for driving synchronous motor

A driving apparatus of a synchronous motor fixes all the switching devices of an inverter at OFF in accordance with a value of an all-OFF control pulse signal outputted by a pulse generator. A motor current keeps flowing through free wheel diodes for a predetermined period even after all the switching devices shift to the OFF state. Therefore, pulse generator changes an induced voltage detection signal to an H (high) level after the passage of the time in which a motor current drops down to zero. A terminal voltage of the motor is taken in to acquire an induced voltage and a rotor position is estimated.

System and method for driving synchronous motor

A voltage detector is connected to a connection terminal connected to one phase of an AC output of an inverter through a diode. A removable charge power supply is connected to said connection terminal and another connection terminal. A charge-power-supply connection judging circuit judges whether the charge power supply is or isn't connected, based on a charge power supply voltage detected by a voltage detector. A mode change control circuit outputs switch signal by the result of said judgment. By receiving this switch signal, the inverter controller switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode. Thereby, a motor drive device detects a connecting status of an external charge power supply and steadily switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode.

Motor drive device that combined charge controller

A method and apparatus for controlling a permanent magnet synchronous motor by accurately detecting 3-phase motor currents from a DC input current in a full voltage range are provided. In the motor control apparatus for detecting the 3-phase motor currents on the basis of the value of the current detected at a DC side of a PWM inverter, when a difference width between PWM pulse signals of two of three phases of the 3-phase PWM inverter which cannot detect the motor currents is not larger than a predetermined value or when the output voltage of the 3-phase PWM inverter is low, the apparatus automatically reduce the carrier frequency of the PWM inverter.

Apparatus and method for controlling AC motor and module therefor

A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source. A output voltages of the power converterare controlled so that the estimated currents Idc, Iqc are equal to respective current instruction values Id*, Iq*. Errors of motor constants are determined from information on the motor currents and the rotational phase errors by an operation.

Apparatus for controlling an a. c. motor

The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input &#x394;&#x3b8;c(=&#x394;&#x3b8;c+&#x394;&#x3b8;c) including an estimated value &#x394;&#x3b8;cin addition to an axial displacement operated value &#x394;&#x3b8;cto the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal &#x394;&#x3b8;c, is added and input. Therefore, actual axial displacement &#x394;&#x3b8;cof the synchronous motor is stable at a value substantially close to zero.

Control method and control device of permanent-magnet type synchronous motor

In a uninterruptible power supply in which a plurality of inverters are operated in parallel, a current control loop is provided which responds to the magnitude of an output current of each inverter brought into parallel running to change a command value for a voltage waveform control circuit associated with each inverter, and the gain of the current control loop is made to be variable, whereby currents shared by the inverters can be set desirably to effectively suppress a cross current flowing between the inverters upon establishment of parallel running.

Inverter apparatus and uinterruptible power supply using the same

A power supply control system including a variable power converter for converting electric power from a power supply to a load into that of a specification required by the load in response to a power specification information source provided on the load side. With a change in the load, the information source also changes, thereby providing a flexible power supply control system capable of meeting different loads. For applications to a high power supply, the system comprises a plurality of variable power converters adapted to operate selectively in accordance with requisite power information sources provided in or on the side of a plurality of loads, thereby providing a system realizing a flexible power supply. For application to a low power supply, the system comprises a plug having a power specification information source and a socket having a variable power converter.

Power supply control system

A structure is disclosed in which instantaneous phase and voltage difference values between the output voltage waveform from an inverter and the output voltage waveform from another AC power source are detected to correct the phase and the level of the output voltage waveform from the inverter so that the phase difference and the voltage difference can be controlled at high speed. As a result, excess current, which occurs if the inverter is operated at high frequencies, can be effectively controlled so that a stable parallel operation of the inverter with another AC power source is possible to perform.

Parallel inverter control apparatus

A mathematical model for simulating a dynamic characteristic of an electric power supply apparatus, a model control function for controlling an output from the mathematical model in a closed loop fashion and an electric power supply apparatus control function for approximating a control variable for the electric power supply apparatus to a reference value are provided in a control circuit, wherein an output from the mathematical model is output as a pulse width reference signal, and the pulse width reference signal is corrected by an on-delay portion due to switching elements by means of a gain revision circuit, thereby promptly and stably controlling the electric power supply apparatus.

Circuit for controlling an electric power supply apparatus, a method

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Hitachi, Japan

Hidefumi Shirahama